Lateral acceleration switch



Apnl 18, 1961 A. B. LEAMAN EI'AL 2,980,773

LATERAL ACCELERATION SWITCH Filed July 1, 1952 2 Sheets-Sheet 1 INVENTORS AUDLEY B. LEAMAN NORMAN CZAJKOWSKI ATTORNEYS April 18, 1961 A. B. LEAMAN ETAL 2,980,773

LATERAL ACCELERATION SWITCH 2 Sheets-Sheet 2 Filed July 1, 1952 INVENTORS AUDLEY B. LEAMAN NORMAN CZAJKOWSKI ATTORNEYS IiATER'AL ACCELERATION swrrcn Audley B. Leaman, Chevy Chase, and Norman Czajkowski, Takoma Park, Md., assignors to the United States of America as represented by the Secretary of the Navy Filed July '1, 1952, Ser. No. 296,777

6 Claims. (Cl. ZOO-61.51)

(Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to switches and more particularly to a lateral acceleration switch. The device of the present invention is mounted preferably in an ordnance missile or projectile of a type which may change course from an initial trajectory during the flight thereof such as disclosed in the copending application of Harold J. Plumley for Method and Apparatus for Steering a Gun-Launched Missile, Serial No. 131,441, filed December 6, 1949.

The switch of the present invention employs a reed having mounted thereon a weighted contact member sensitive to forces perpendicular to the axis of the missile such as those present when such a missile changes course. The switch may be employed to fire an electroresponsive detonator such as that used to actuate the arming device asset forth in the copending application of Eugene L. Cecil, Jr., Serial No. 240,020, filed August 2, 1951, now Patent No. 2,830,539, for Arming Device for a Fuze. Apparatus is provided to maintain the reedmounted contact member against movement until a setback force, such as that received by the device during 3 launching, is received.

An object of the present invention is to provide a new and improved electrical switch operative to close a circuit when influenced by a lateral force.

Another object is to provide a new and improved apparatus for firing a detonator which is maintained safe prior to arming.

Still another object is to provide an improved switch apparatus which in the armed position is positive in action when a lateral force of sufiicient intensity is received thereby.

A further object is to provide an improved switch for actuating an arming device which is simple, rugged and inexpensive to manufacture.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following' detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a vertical sectional view of a preferred form of the present invention and showing the parts in the safe position;

Fig. 2 is a view similar to Fig. 1 and showing the parts in the armed position;

Fig. 3 is a circuit diagram showing the conditions as in Fig. 1; I 1

Fig. 4 is a circuit diagram showing the conditions as inFig. 2; and p Fig. 5 is a vertical sectional view of an alternate form of the present invention.

Referring more particularly to the drawings wherein like numerals'indicate like parts throughout the several Patented Apr. is, real a bore 11. The bore .11 is provided with a reduced portion 12 forming shoulders 13 and 14 and enlarged end portions 15 and 16 forming shoulders 17 and 18 respectively.

An insulating cylindrical member 19 having a head portion 21 is inserted in bore 11, head 21 engaging shoulder 18 and being retained by upsetting the edge of casing 10 as at 22. Member 19 is formed with a bore 23 having a tapered portion 24 and has threaded therein views, 10 indicates generally a cylindrical casing having at one end thereof a plug 25, the metal plug 25 being secured in the portion 24. A metal reed or wire 26 is fixed in plug 25. Reed 26 extends into bore 23 and has a weighted metal contact member 27 secured to the free end thereof.

An annular contact member 28 is mounted in an insulating ring 29 set in bore 11 between shoulder 14 and the inner end of member 19. A conductor wire 31 is secured to ring 28 as at 32. It will be seen that if the device is subjected to a lateral force of sufiicient magniture contact member 27 by inertial force will strike contact member 28, thus momentarily closing a circuit to fire an electroresponsive detonater 33 as shown in Figs. 3 and 4 and will be hereinafter more fully described.

Mounted in bore 15 and resting against shoulder 17 is a metal insert member 34 having an internal step out 35 at the edge of bore 36 in member 34 and a reduced opening 37 in the outer wall thereof. A metallic piston head 38 is slidably fitted in the upper extension of bore 11 and is adapted to slide into bore 36. Piston head 38 is provided with a pair of circumferential grooves 39 and 41. Groove 39 initially has a spring locking ring 40 with half the thickness thereof within groove 39 and half within step-cut 35. Between the depth of groove 39 and the edge of groove 41 there is provided a slightly tapered portion 42 which prevents movement of piston 38 until a suflicient axial force is encountered thereby.

Piston head 38 has threaded or otherwise secured therein a sleeve 43 of electrical insulating material which is of a diameter sufficient to slidably fit in contact member 28 and has a pair of diametrically opposed longitudinal grooves 44 formed therein. Fixedly mounted in grooves 44 are spring contact members 45 which engage tion. The contacts 45 engage piston head 38 thus connecting member 28 to the casing 10 which is grounded. v

The sleeve 43 extends over the contact member 27 on reed 26 and receives member 27 in the bore 46 thereof. Spring 47 is interposed between piston head 38 and insulating ring 29 and urges the piston assembly 48, comprising head 38, sleeve 43, and contacts 45, in' a direction toward'the end of casing 10 having the insert 34.

In operation, the switch of the present invention is mounted in an ordnanec device such as a projectile or missile with the longitudinal axis thereof in alignment with the direction of flight (indicated by the arrow A); When the device is launched, set-back force, in a direction opposite to the direction of flight, moves piston assembly 48, compressing spring 47 until the piston strikes shoulder 13. During this movement of piston assembly 48, spring locking ring 40 is dislodged from groove 39 and moves over tapered portion 42 and into groove 41. Groove 41 being of less diameter than groove 39, ring 40 drops into groove 41 and out of step out 35 thus unlocking piston assembly 48. As the setback force diminishes, spring 47 forces the piston assembly against shoulder 49 of bore 36, withdrawing the assembly from the contact member 27, thus freeing the member 27 for lateral movement and also freeing member 28 from contact with ground by moving contacts 45 out of engagement with member 28.

When the missile changes course, as described in the aforementioned application for Method .and Apparatus for Steering a Gun-Launched Missile, the lateral forces resultant therefrom cause the contact member 27 to flex the reed 26 'thus'to engage annular contact 28 and to close the: arming circuit which will be hereinafter more:

fully described. i

As shown in the electrical diagrams of Figs.- 3 and4,

:t'a'cts 45 connect annular ring 23 to' ground as'at 51 to prevent accidental firing of the el ectrorespgonsive :detonator 33; it is, of course, clear that contact member 27 is. held against movement by the insulating sleeve 43, thus tiring of the detonator is prevented m the safe'position by:

. spectively inretaining washer. 57 andinertia member. 56.

it is, of course, apparent that there is no appreciable I difference inthe electrical circuit of the two forms ofthe the piston d8 (Fig; 3) is in the safe positionand :con-

invention, therefore, only one form has been shown in the drawings.

Obviously many modifications and variations of the presentinvention' are possible in the light of the above teachings. It is therefore to be understood that within the scope of'the appended claims the invention may be practiced otherwise than as specifically described 'What isclaimed as new and desired to be secured by Letters Patent of the United States is:

grounding both sides of the detonator circuit and by i holding'mentber '27 against movemenh Reed 26 is com nected to the battery or other source of power 52, the

other side of battery 52 being grounded.

In the armed position, as shown inthe diagram of Fig. 4 piston 43 has moved away from: ring 28 breaking= 7 the connectioniofthe ring-with ground. Contact 27 hasalso been freed to permit lateral motion when a lateral a shock or force is received by the device. When'contact 27 engages'ring' 28 a detonator firing circuit is closed from groundto battery 52, through reed 26, contact 27,

' ring 28, conductor 31- to detonator: 33 and=thence to.

ground.

= The detonator' 33 may .be employed inthe same mandrical member 19, the annular contact member 28, the

insulating. ring 29, conductor .31, plug 25, reed .26 and contact member 27 are all similar to those parts of the preferred form of the invention.

Casings?) 'ofthemodification is formed with a re raining lip 54 forming a wall between bore .11 and bore 55, An inertia member 56 is set in the endof thecasing. 53 opposite to that occupied by cylindrical member 19 and in bore 55. A retaining washer 57 forms a closure for bore 55 of casing 53. Inertia member 56 is mounted in bore 55 for movement against the tension of spring 59. An axial bore 61 is formed in inertia member 56 and has a circumferential groove 62 adjacent the lower lip thereof. A piston 63 is mounted in bore 55 between inertia member 56 and retaining lip 54. Reduced portion 64 of piston 63 is provided with arcuate shoulder 65 and initially has a locking ring 66 resting thereagainst. Ring 66 also rests against shoulder 67 f member 56 thus holding member 56 and piston 63 in the safe position, as shown in Fig. 5. 7

An insulating sleeves 68 is threaded into piston 63 as at 69 and is provided with a pair of diametrically opposed grooves 71. A pair of contacts 72 are set in bores '73 in piston 63 and extend along grooves 71 to engage annular ring 23, thus connecting ring 28 to casing 16 which is grounded as in the preferred form of the invention.

In operation, the direction of travel is in the direction of arrow A and the launching of the missile in which the device is mounted produces a set-back force which moves inertia member 56 in a direction opposite to that indicated by arrow A. As member 56 moves, ring 66 is expanded over shoulder 65 and into groove 62 and moves along face 74 until it drops into a groove '75. When the set-back force subsides, spring 59 moves inertia member 56 back to the initial position thereof, and by reason of the ring 66 being locked in grooves 62 and 75, carries piston 63, sleeves 6S, and contacts 72 to an armed position, freeing contact member 27 for lateral motion and disconnecting the member from ground as in the preferred form of the invention. In order to permit free movement of piston 63 in bore 61 and inertia member 56 --in bore 55, air passages 76 and 77 are formed re- 'LA switch for arming an ordnance; device compris' i'ng, acasing, a generally cylindrical insulating member disposedin'one end of said casing, a reed axially mounted. internally of. said member, :meanszforsecuring one. end of said reed in said member, a weightedmovable con-v 1 tact member mounted on the free end ofsaid reed-forlateral motion therewith, said reed havingaxial, stiffness and lateral flexibility, a slidable locking-means normally disposed about saidmovable contact member and releasable therefrom in response to the application .ofa

setback force thereto as. the. missileis launched, and an annular contact member fixed in the inner periphery of said insulating member and insulated from said casing,

said annular contact member being in radially spaced relation fromsaid movable contact member and adapted to be engaged by said nrovablecontact member only after setback'release ofsaid locking member and when influenced by. a lateral force, thereby to close an electri- Q cal 'circuit'therethrough. 1

2. Apparatus for arming an ordnance device comprising, in combination, acylindrical casing, a sliding piston having 'a circumferential groove therein and mounted in 'saicl'casing, a complementary step'formed'in said casing,

a yieldable-ring mounted to normally engage the groove said-casingand for; initially holding said piston in the safe position until said piston is displaceditherefrom by a set-back force of s'ufiicient magnitude, :ametal reedhaving an inertia responsive metallic contact formed on one end thereof, means for supporting said reed at a point spaced from said contact, insulating means for releasably restraining said inertia responsive contact against lateral motion, said restraining means being fixed to said piston for motion therewith whereby the restraining means is moved to release the metallic contact therefrom as the piston is moved by said set-back force, said metallic contact when released being free for lateral movement when subjected to a lateral force of sufficient magnitude, and a contact ring fixed in said casing in spaced adjacency to said metallic contact and adapted to be contacted by said metallic contact to close an electrical circuit when said metallic contact moves laterally.

3. Apparatus for arming an ordnance device subjected to an initial set-back force along the axis thereof and a second force laterally thereof comprising, in combination, a casing, a fixedly mounted cantilever reed element, a reed-supported contact member disposed on one end of said reed in a manner to be responsive to a lateral force, a ring shaped contact member fixedly supported within said casing and in'spaced adjacency to said inertia responsive contact, releasable retaining means for normally reraining said inertia responsive member against lateral movement said retaining means being responsive to setback force for releasing said inertia responsive member when said initial set-back force is received, said retaining means including a spring ring means disposed between a portion of said retaining means and said casing for retaining said releasable retaining means and for releasing said releasable retaining means when a set-back force of suflicient magnitude is received. p l

4. Arming apparatus for an ordnance device comprising, in combination, a casing, a reed having a free end and a supported end mounted axially within said casing,

a weighted circuit closing member mounted on the free end of said reed, said circuit closing member being responsive to forces in a direction lateral to the line of flight of said ordnance device, means for restraining said contact member against lateral motion, and means for releasing said restraining means, said releasing means being responsive to forces along the line of travel of said ordnance device.

5. Apparatus for arming an ordnance device subjected to an initial set-back force along the axis thereof and to a sequentially applied force acting laterally thereof which comprises a casing, an inertia member mounted within said casing for movement therein when said set-back force is received, a spring mounted in abutting relation with said inertia member and adapted to be compressed by said inertia member as said set-back force is received, said inertia member having an axial bore having a shoulder and an adjacent groove therein, a piston mounted adjacent said inertia member and partly within said bore, said piston having a rounded shoulder thereon, a locking ring mounted between said shoulder and said rounded shoulder, a groove in said piston in spaced adjacency to said rounded shoulder, a cylindrical member of insulating material secured to said piston and having an axial socket therein, a pair of contact members secured to said cylindrical member and to said piston, a ring-shaped contact member fixedly mounted in said casing and insulated therefrom, a movable contact member, and a reed having said movable contact member secured to one end thereof and having the other end thereof secured to the casing and insulated therefrom, said movable contact being initially axially mounted within said socket and in alignment with said ring-shaped contact, said reed supporting said movable contact for lateral motion and having resistance to axial motion, said inertia member when moved by said set-back force being disposed to carry said locking ring over said rounded shoulder and into said groove in said piston thereby locking said inertia member and said piston together, said spring forcing said inertia member to the initial position thereof and said inertia member carrying therewith the piston and cylindrical member and contacts thereof out of engagement with the movable contact and the ring shaped contact respectively.

6. Apparatus for arming an ordnance device subjected to an initial set-back force along the axis thereof and a second force laterally thereof comprising in combination, a casing, inertia means mounted within said casing and movable axially from an initial to a moved position by said set-back force, a spring for returning said inertia means to the initial position, a locking ring movable from an initial position to locking position, means on said inertia means for moving said locking ring from said initial position to said locking position, movable contact means responsive to lateral shock, fixed contact means adapted to be engaged by said movable contact means when said movable contact means responds to a lateral shock, and means for preventing response of the movable contact means to said lateral shock engageable by said locking ring in the locking position thereof, said response preventing means being disengaged from said movable contact means when the inertia means is returned to the initial position.

References Cited in the file of this patent UNITED STATES PATENTS 1,471,628 Palmer Oct. 23, 1923 1,656,704 Golombrowski Jan. 17, 1928 2,364,010 Underwood Nov. 28, 1944 2,458,464 Busacker et a1. Jan. 4, 1949 2,498,040 Jordan et al Feb. 21, 1950 2,618,712 Moledzky Nov. 18, 1952 FOREIGN PATENTS 864,381 France Apr. 25, 1941 

